Stone, masonry, concrete, unglazed tile, brick, porous clay and various other substrates with surface porosity are used decoratively in the indoor and exterior environment. However, oils, hydraulic fluids, and oily and aqueous foodstuffs, including, for instance, oils, coffee, ketchup, salad dressings, mustard, red wine, other beverages, and fruit preserves easily stain such surfaces. Many of the prior art treatments, such as clear sealants based on polyurethanes or epoxies, disadvantageously alter the appearance of the substrate. Such sealants can also trap moisture within the treated substrate, promoting spalling.
Longoria, et al. in U.S. Pat. No. 6,271,289, describe a composition providing stain resistance to stone, masonry and other surfaces comprising a mixture of anionic fluoroalkyl phosphates and anionic fluoroacrylate polymers.
Fluorochemical copolymers, typically as aqueous dispersions, are used to impart water resistance and oil and grease repellency to paper and textile fibers as well as to calcitic and/or siliceous architectural and construction materials. Conventional commercial dispersions and dispersions having a low pH tend to etch marble and other calciferous substrates.
It is desirable to have compositions wherein the anionic phosphate can be combined with cationic polymers that provide superior oil and water repellency, stain resistance, and improved compatibility with substrate surfaces such as marble and limestone that are calcium carbonate compositions and thus susceptible to etching. The present invention provides such a composition.